of tipton



UNITED STATES PATENT OFFICE.

FRAN K PERRY, 0F TIPTON, ENGLAND, ASSIGNOR TO INDUSTRIAL INVENTIONS LIMITED, 0F TIPTON, ENGLAND.

"PRODUCTION OF MALLEABLE-IRON CASTINGS.

No Drawing.

To all whom it may concern:

Be it known that I, FRANK PERRY, residing at 68 Dudley road, Tipton, in the county of Stafford, England, a subject of the King of Great Britain and Ireland, have invented certain new and useful Improvements Relating to the Production of Malleable-Iron Castings, of which the following is a specification.

Iron castings are ordinarily malleableized or softened by prolonged heating in powdered or granular solid materials such for example as iron oxid for producing White heart malleable castings or an inert substance such for example as sand for obtaining black heart malleable castings.

The present invention consists in the decarbonizing or modifying the carbon constituent of iron castings, by heating them in the presence of industrial gases of the producer gas type containing carbon dioxid associated with hydrogen.

It is desirable to have present such a proportion of carbon monoxid as will prevent any serious decomposition of the carbon dioxid by hydrogen at the working temperature. Also it is preferable to previously remove all sulfur and hydrocarbon compounds from the gas to avoid absorption of sulfur by the iron, and the tendency of the hydro-carbon to reverse the decarbonizing action. These conditions are fulfilled by the use of Mond, blast furnace, or other lik gases of the producer gas type.

In practice the articles to be malleableized are placed in suitable receptacles and heated a slow stream of such gases as those abovementioned, being simultaneously passed through the receptacles, the normal temperature of treatment lying between 800 degrees and 950 degrees centigrade, for producing white'heart castings and between 700 and Specification of Letters Patent.

Patented Oct. 21, 1919.

Application filed February 6, 1919. Serial No. 275,362.

will prevent ingress of extraneous air or flue gases, the temperature for obtaining black heart castings being kept lower than that used for obtaining white heart castings.

Preferably at the end of the malleableizing process the articles may be cooled while in the presence of the gas so as to avoid oxidization by air.

When operating at temperatures of 850 degrees centigrade and upward with gases freed from sulfur compounds I have found that the sulfur content of the iron can be lowered.

l have also found that the graphitic carbon in gray cast irons may be eliminated by the above described process, although at a slower rate.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is The production of malleable iron castings by heating iron castings suitable for malleableizing in the presence of industrial gases of the producer gas type containing carbon dioxid associated with hydrogen.

In testimony whereof I have signed my name to this specification.

FRANK PERRY. 

